The trend in the design of blades for an axial flow machine is toward increasing the aspect ratio of the blades and making the blades thinner. The blades designed in such a way tend to flutter during the operation of the axial flow machine. The fluttering is a self-induced vibration at the natural frequency of the blade. This vibration may be a longitudinal vibration of the blade with a vibration node at the root of the blade. Energy is thereby transferred from the fluid flowing in the axial flow machine to the blade. With repeated load changes of the axial flow machine, the fluttering may lead to material fatigue of the blade (high cycle fatigue). The material fatigue may lead to the formation of a crack and necessitate a cost-intensive replacement of the blade.
Fluttering is conventionally prevented by reducing the load acting on the blade. This however disadvantageously leads to a reduction in the efficiency of the axial flow machine. Furthermore, damping elements are conventionally provided, such as for example a shroud, which damps the fluttering of the blades. This however is a structurally complex solution. It would therefore be desirable to design the blade in such a way that it does not tend to flutter during the operation of the axial flow machine.